scholarly journals Detection of Weak Transient Signals Using a Broadband Subspace Approach

Author(s):  
Stephan Weiss ◽  
Connor Delaosa ◽  
James Matthews ◽  
Ian K. Proudler ◽  
Ben A. Jackson
Keyword(s):  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Claude Lormeau ◽  
Fabian Rudolf ◽  
Jörg Stelling

AbstractCells can encode information about their environment by modulating signaling dynamics and responding accordingly. Yet, the mechanisms cells use to decode these dynamics remain unknown when cells respond exclusively to transient signals. Here, we approach design principles underlying such decoding by rationally engineering a synthetic short-pulse decoder in budding yeast. A computational method for rapid prototyping, TopoDesign, allowed us to explore 4122 possible circuit architectures, design targeted experiments, and then rationally select a single circuit for implementation. This circuit demonstrates short-pulse decoding through incoherent feedforward and positive feedback. We predict incoherent feedforward to be essential for decoding transient signals, thereby complementing proposed design principles of temporal filtering, the ability to respond to sustained signals, but not to transient signals. More generally, we anticipate TopoDesign to help designing other synthetic circuits with non-intuitive dynamics, simply by assembling available biological components.


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
M Leth-Olsen ◽  
G Doehlen ◽  
H Torp ◽  
SA Nyrnes

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Joint Research Committee between St. Olavs Hospital and the faculty of Medicine, NTNU. The Norwegian Association for Children with Congenital Heart Disease Research Foundation, FFHB Background   There is a risk of gaseous- and solid micro embolus formation during transcatheter procedures (CATH) and surgery in children with congenital heart disease (CHD). Silent strokes during surgery or CATH may contribute to neurological impairment. NeoDoppler is a non-invasive ultrasound system based on plane wave transmissions to continuously monitor cerebral blood flow in infants with an open fontanelle. Gaseous- and solid micro embolus passing through the ultrasound beam create High Intensity Transient Signals (HITS) in the Doppler signal.  Purpose We aimed to study the amount of HITS during CATH and surgery in infants using NeoDoppler.  Methods   The NeoDoppler probe operates at a frequency of 7.8 MHz. The frame rate is 300 fps and the beam covers a wide cylindrical area (10/35mm width/depth). The system displays a color M-mode Doppler and a spectrogram. The broad ultrasound beam permits prolonged scanning time of each event as the HITS move through the ultrasound beam. The high framerate and color M-mode allows for tracking of embolies in depth. In this study the NeoDoppler probe was attached to the anterior fontanelle of infants with CHD during CATH (n = 15) and cardiac surgery (n = 13). HITS were defined as high intensity signal creating skewed lines in the color M-mode Doppler moving away or towards the probe (blue/red) with a corresponding high intensity signal in the spectrogram. HITS were grouped into single HITS and HITS with curtain effect. Single HITS were defined as single skewed lines in the color M-mode Doppler and spectrogram. HITS with curtain effect were defined as skewed broad lines or multiple intensity increase lines in the color M-mode Doppler with corresponding intensity increase that filled the entire doppler curve. HITS with curtain effect are believed to represent numerous HITS that could not be separated from each other in the spectrogram. HITS were manually detected in an in-house MatLab application. Results   The study group consisted of 28 infants (17 males) with different CHD who underwent CATH or surgery. The median age and weight was 96 days (range 3-240 days) and 5650 g (range 2400-8085 g). HITS were detected in 13/15 patients during CATH with a total of 392 HITS (Median 12, Range 0-149) and in all patients during surgery with a total of 772 HITS (Median 45, Range 11-150).  The picture shows examples of single HITS (panel A) and HITS with curtain effect (panel B). One can appreciate the embolic trajectory pattern in depth over time in the color M-mode Display.  Conclusion   In this study we found that NeoDoppler enables detection of frequent HITS in patients with CHD undergoing surgery or CATH. NeoDoppler could become a useful tool to guide modifications of procedures, with aim to reduce the risk of silent stroke. However, further studies are needed to validate the technique. Abstract Figure.


2003 ◽  
Vol 17 (2-3) ◽  
pp. 123-127 ◽  
Author(s):  
Kazumi Kimura ◽  
Jacinda L. Stork ◽  
Christopher R. Levi ◽  
Anne L. Abbott ◽  
Geoffrey A. Donnan ◽  
...  

2014 ◽  
Vol 29 (9) ◽  
pp. 1607-1617 ◽  
Author(s):  
Alkiviadis Gourgiotis ◽  
Sylvain Bérail ◽  
Pascale Louvat ◽  
Hélène Isnard ◽  
Julien Moureau ◽  
...  

This work provides a simple method for isotope ratio drift correction in MC-ICPMS transient signals.


1971 ◽  
Vol 42 (10) ◽  
pp. 3866-3869 ◽  
Author(s):  
James R. Wait ◽  
David A. Hill

Author(s):  
Kota Yamamoto ◽  
Hisashi Asanuma ◽  
Hiroaki Takahashi ◽  
Takafumi Hirata

New data reduction method for isotopic measurements using high-gain Faraday amplifiers enables precise uranium isotopic analysis even from transient signals.


Sign in / Sign up

Export Citation Format

Share Document